Chevy experimental cam
Thread Starter
Instructor
Joined: Feb 2004
Posts: 141
Likes: 4
From: Scottsdale AZ
Chevy experimental cam
No specs available on this cam and have not been very happy with performance for this L98 TPI in my 58 using factory timing. Yesterday gave the distributor about 15 degrees more advance without using a light and it's running much better. No ping and runs great. Anyone know of any real down side to timing like this on a computer engine? It's just the way I used to time carbureted engines - max performance with no ping and easy start.
Last edited by mr-natural; Nov 28, 2011 at 10:23 PM.
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 78
From: Monroe OH
NCM Sinkhole Donor
No specs available on this cam and have not been very happy with performance for this L98 TPI in my 58 using factory timing. Yesterday gave the distributor about 15 degrees more advance without using a light and it's running much better. No ping and runs great. Anyone know of any real down side to timing like this on a computer engine? It's just the way I used to time carbureted engines - max performance with no ping and easy start.
Team Owner
Joined: Sep 2003
Posts: 20,179
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
Had the same problem with my Comp Cam mod. Just kept cranking up the base timing until it pinged. Ended at almost 20 advanced. Checked the timing marks with the piston stop. Checked distributor position. Double checked the knock sensor operation and timing map. The cam just wanted more base than most would agree with. My final is 16 BTDC with the wire pulled. Runs correctly in all temperatures and conditions without knocking on reg fuel.
Been driving her for three years without problems.
Been driving her for three years without problems.
Last edited by JrRifleCoach; Nov 28, 2011 at 11:11 PM.
Thread Starter
Instructor
Joined: Feb 2004
Posts: 141
Likes: 4
From: Scottsdale AZ
Hey, L98TPI, JrRifleCoach, and The 383 Admiral,
I've been having such a ball driving this thing lately I just now got back to check my post. Thanks for your input, I agree I need to get a scan tool to see what's happening. Fun, fun and more fun.
I've been having such a ball driving this thing lately I just now got back to check my post. Thanks for your input, I agree I need to get a scan tool to see what's happening. Fun, fun and more fun.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Had the same problem with my Comp Cam mod. Just kept cranking up the base timing until it pinged. Ended at almost 20 advanced. Checked the timing marks with the piston stop. Checked distributor position. Double checked the knock sensor operation and timing map. The cam just wanted more base than most would agree with. My final is 16 BTDC with the wire pulled. Runs correctly in all temperatures and conditions without knocking on reg fuel.
Been driving her for three years without problems.
Been driving her for three years without problems.
I had a 350 with a 234/244 cam and ~8:1 compression w/aluminum heads (I didn't put this engine together!). What this particular engine "liked" with so much cam and such low compression was "flat/fixed" timing; about 32* base and 32* through the range. Yikes.
Team Owner
Joined: Jul 2004
Posts: 28,424
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From: Hartford WI
Yesterday gave the distributor about 15 degrees more advance without using a light and it's running much better. No ping and runs great. Anyone know of any real down side to timing like this on a computer engine? It's just the way I used to time carbureted engines - max performance with no ping and easy start.
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From: Texas
Sorry...To install a cam and not know the specs is beyond insane.
A computer controlled engine responds to timing just like a carb'ed one, albeit with better control. None the less, too much timing on a computer engine will burn a valve just like on a carb'ed engine.
You want to fix it? Install a cam that you've matched to the rest of the engine.
